Researchers, while writing manuscripts, often use the abbreviation 'et al.'. It means

The abbreviation et al. is short for the Latin et alii, meaning and others.

It is used to shorten a citation with many authors after naming the first one or two.

Extra alternate has no connection to the meaning of et al.

At the end is not what this Latin phrase conveys.

And alternatively misstates the sense, which is simply and others.

APA style uses et al. for works with three or more authors from the first citation.